INGREDIENTS
4 oz
or 113 grams) unsalted butter
1/2 cup
dark brown sugar, packed
1/3 cup
granulated sugar
1
large egg
145 g
(about 1 cup plus 2 tablespoons) all-purpose flour
1/2 tsp
baking soda
3/4 tsp
kosher salt
2/3 cup
finely chopped chocolate
1/3 cup
toffee bits